The present invention relates to a timing device for controlling the operation of a printing machine.
Known are numerous designs of decentralized timing devices for use in printing machines which are adjusted to a specific operational function of the machine such as for example the synchronized control of sheets, sequentially correct feeding and discharging of prints, time controlled sorting of sheets and the like.
Known is also a control system for multicolor rotary printing machines which controls the actuation of individual printing units with the machine or of individual functional groups in each printing unit so as to guarantee the passage of a sheet through the machine in correct sequence and at accurate time points. This known control system, described for example in the German Patent No. 2,220,601, employs an impulse stage for generating timing signals corresponding to an integer part of rotation of a cycle shaft of the machine that is to an integer angular position of the cycle shaft. The impulse stage consists of a signal generator, an interrogating circuit, a signal shaper and a closed shift register.
The disadvantage of this known system is its limited field of application. This known pulse stage is designed for controlling only one partial operation of the machine and consequently it is necessary to employ a large number of such timing devices in the printing machine.
Another disadvantage is to be seen in the fact that this known pulse stage generates only non-modified timing signals and cannot be used for the production of timing signals which are adjusted in response to the rotary speed of the machine, for example. This speed adjustment is necessary for the control of non-operative times of numerous setting members of the printing machine. Furthermore, in these prior art control devices it is necessary to use pulse shapers for generating pulses of different length but these pulse shapers can produce only a preset, non-adjustabe pulse length.